Diabetes mellitus is a group of diseases characterized by high levels of blood glucose resulting from defects in insulin production, insulin action, or both. According to current estimates, 17 million people in the U.S., or approximately 6.2% of the population, have diabetes. Over 8% of adults (age 20 or older) have diabetes, while over 20% of Americans age 65 or older have the disease. Approximately 90-95% of all people diagnosed with diabetes have adult-onset, or Type 2 diabetes. The remaining 5-10% of people with diabetes (generally children and young adults) have insulin-dependent, or Type 1, diabetes. The risk of developing diabetes increases with age or obesity levels. One million new cases are diagnosed in adults each year. In 1999, approximately 450,000 deaths due to diabetes occurred among people 25 years or older. This figure represents about 19% of all deaths in this age group. Complications of diabetes include heart disease, stroke, high blood pressure, blindness, kidney disease, nervous system disease, amputations, dental disease, and complications during pregnancy.
In order to survive, people with Type 1 diabetes must have insulin delivered by a pump or injections. People with Type 2 diabetes may be able to control their blood glucose by following a careful diet and exercise program, losing excess weight, and/or taking oral medication. Many people with diabetes also need to take medications to control their cholesterol and blood pressure. Among adults with diagnosed diabetes, about 11% take both insulin and oral medications, 22% take insulin only, 49% take oral medications only, and 17% do not take either insulin or oral medications. Most non-insulin therapies are oral drugs designed to either lower blood glucose levels or improve the sensitivity of the body's insulin to varying glucose levels. Oral anti-diabetics account for about 63% of the total anti-diabetic drug sales. Glucophage (metformin) had been the leading product, and it works by keeping the liver from making too much sugar, but it does not work for everyone, and effectiveness typically decreases over time. A newer class of drugs, insulin-sensitizers, lowers insulin resistance to help a diabetic's declining levels of insulin work harder and go farther. Currently marketed insulin-sensitizers are the two glitazones, Actos® and Avandia®. These two insulin-sensitizers are designed to be used as monotherapy or in combination with other antidiabetic drugs. However, glitazones have been associated with liver toxicity and death, so physicians remain cautious about the use of these drugs. There is a vast clinical need for safer and more effective therapies to treat diabetes.
Lactoferrin is a single chain metal binding glycoprotein. Many cells types, such as monocytes, macrophages, lymphocytes, and brush-border cells, are known to have lactoferrin receptors. Lactoferrin is found mainly in external secretions of mucosal epithelia such as breast milk, saliva, tears, bile, and pancreatic fluid and has a wide array of functions related to host primary defense mechanisms. For example, lactoferrin has been reported to activate natural killer (NK) cells, induce colony stimulating activity, activate polymorphonuclear neutrophils (PMN), regulate granulopoeisis, enhance antibody-dependent cell cytotoxicity, stimulate lymphokine-activated killer (LAK) cell activity, and potentiate macrophage toxicity.
The present invention is the first to use a lactoferrin composition as a means of lowering glucose levels as a treatment for diabetes mellitus.